Pressure regulating valve apparatus

ABSTRACT

A fluid pressure regulating valve apparatus for controlling either upstream or downstream fluid pressure includes a lower housing including a lower interior space and an upper housing including an upper interior space which is separated from the lower space by a deformable diaphragm. The diaphragm and lower space together define a substantially smooth, generally void free fluid receiving cavity with which first and second conduits are connected. The first conduit includes a constriction and the second conduit is angled relative to the first conduit. A valve is provided including a valve closure member movable between flow-permitting and flow-preventing positions. An upper stem element is connected to the diaphragm and extends through the upper interior space to an upper end disposed exterior of the upper housing such that pressure regulation and regulator adjustment may both be carried out from outside the lower housing.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to flow control valves and, moreparticularly, to an apparatus for regulating either the upstream ordownstream pressure of fluid being controlled by the apparatus.

2. Description of the Prior Art

It is known to provide valve devices in fluid supply systems forcontrolling the fluid pressure at a desired location in the system. Forexample, in a fluid dispensing arrangement, it is conventional toprovide a pressure regulating valve apparatus upstream of a dispensingdevice in order to control the pressure of fluid being pumped to thedispensing device.

In this known type of system, the regulating device is referred to as adownstream pressure regulator because it controls the pressure of fluiddownstream of the valve apparatus and maintains a desired predeterminedpressure of fluid at the dispensing apparatus. It is also possible tohave similar applications where an upstream regulating valve apparatusis used which maintains a predetermined pressure in the fluid upstreamof the valve.

Although these known pressure regulating devices have been foundsatisfactory in numerous applications, certain drawbacks are evidentwhen such devices are employed in systems requiring a regulation of thepressure of clean fluids such as ingestible medicines or beverages. Inthe food industry, it is necessary to provide a relatively smoothsurface throughout the flow path of fluids being dispensed in order toreduce the opportunity for the fluid to get caught up within the systemand stagnate. Thus, it is important to present as few voids andinterstices as possible to the fluid in an effort to reduce suchstagnation. Further, frequent cleaning of all fluid dispensing equipmentis necessary in order to protect against the presence of germs in thesystem which adversely effect the quality of the fluids being handled.

In view of these special needs in the food and medicine industries, itmay be understood that a regulating device having a complex internalmechanical construction would not be well suited for use in regulatingthe pressure of an ingestible fluid. Such intricate constructions resultin a device which is difficult to clean and which permits fluid to getcaught up in voids and interstices within the fluid flow path such thatstagnation is promoted.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide a pressureregulating apparatus which overcomes the drawbacks noted above and whichis capable of use in regulating fluid pressures within systems forhandling ingestible fluids such as clean gases, medicines and beverages.

It is another object of the invention to provide a pressure regulatingapparatus which permits ready confirmation of the position of a valveclosure member from a position exterior of the apparatus in order tosimplify the use of the device and improve the safety considerationsinvolved in its use.

Further, yet another object of the invention is to provide a fluidpressure regulating apparatus capable of being locked in aflow-permitting position so that the apparatus may be cleaned withoutupsetting the pressure level at which a regulating means of theapparatus is positioned.

In accordance with one aspect of the invention, a fluid pressureregulating valve apparatus includes a lower housing including a lowerinterior space, an upper housing assembly including an upper housingdefining an upper interior space, and a deformable diaphragm separatingthe lower interior space from the upper interior space. The diaphragm,together with the lower interior space, defines a fluid receivingcavity, and first and second conduits communicate with the fluidreceiving cavity, the second conduit being offset from the firstconduit.

A valve is provided including a valve closure member connected with thediaphragm so that the closure member and diaphragm are movable togetherbetween a flow-permitting position and a flow-preventing position. Anupper stem element is also connected to the diaphragm and extendsthrough the upper interior space. An upper end of the upper stem elementis disposed exterior of the upper housing.

The upper housing assembly further includes pressure regulating meansfor exerting a force on the diaphragm in a direction toward the lowerinterior space and regulating adjustment means for adjusting the forceexerted on the diaphragm by the pressure regulating means.

According to other particular aspects of the invention, preferreddownstream and upstream pressure regulating apparatuses are providedwhich are easy to clean and present smooth, relatively void-free fluidreceiving cavities such that stagnation of fluid within the cavities isinhibited.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

A preferred embodiment of the invention is described in detail belowwith reference to the attached drawing figures, wherein:

FIG. 1 is a schematic view of a fluid utilization system incorporating adownstream pressure control valve apparatus which is constructed inaccordance with the present invention;

FIG. 2 is a side sectional view of a downstream pressure control valvein accordance with the invention;

FIG. 3 is a side sectional view of an upstream pressure control valveconstructed in accordance with the invention;

FIG. 4 is a top sectional view of the downstream control valve of FIG.2;

FIG. 5 is a partial front elevation view of the downstream pressurecontrol valve of the present invention;

FIG. 6 is a bottom plan view of an inlet conduit of the downstreampressure control valve apparatus of FIG. 2; and

FIG. 7 is a bottom plan view of an inlet conduit of the upstreampressure control valve apparatus of FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A fluid utilization system is illustrated in FIG. 1, which incorporatesa downstream pressure regulating valve apparatus 10 constructed inaccordance with a preferred embodiment of the present invention.

The fluid system includes a dispensing apparatus 12 for measuring outand dispensing a fluid product into portions suitable for bottling orpackaging. A source of fluid, such as a tank or other container 14 ofknown construction is connected to the dispensing apparatus via aconduit 16, and a pump 18 is provided in the system to pressurize thefluid delivered to the dispensing apparatus.

The pressure regulating valve apparatus 10 is interposed between thepump 18 and the dispensing apparatus 12 for controlling the pressure ofthe fluid downstream of the valve apparatus such that the fluid at thedispensing apparatus is maintained at a generally constant pressure. Byproviding such regulation of the pressure of the fluid at the dispensingapparatus 12, it is possible to provide an accurate dispensingoperation.

The pressure regulating valve apparatus 10 is shown in more detail inFIG. 2, and includes generally a lower housing 20 and an upper housingassembly 22. The lower housing 20 includes a lower interior space 24including a surface adapted to be exposed to fluid being handled by theapparatus. The exposed surface of the interior space 24 is relativelysmooth, preferably being formed by polishing with various polishingexpedients until the roughness is less than about 15 R_(a), which is anaccepted roughness in the food industry for contact surfaces in fluidtreatment devices.

Inlet and outlet conduits 26, 28 are formed in the lower housing 20which are each in communication with the lower interior space 24 andwhich are offset from one another, preferably by an angle of aboutninety degrees. The inlet and outlet conduits 26, 28 include interiorsurfaces which, like the surface of the lower interior space 24, arepolished to a surface roughness accepted by the food industry, and theinlet conduit 26 includes a constriction 30 having a function describedbelow. Further, each conduit 26, 28 is preferably provided with a flange32, 34 adjacent a termination end thereof which permits attachment ofthe apparatus 10 to the conduit 16 of the fluid handling system. Otherknown connection expedients, such as butt welding may, of course, beused.

A flange 36 is formed in the lower housing 20 adjacent an open end ofthe lower interior space 24 located opposite the inlet conduit 26, anddefines a diaphragm bearing surface on which a diaphragm 38 is seatedwhen the apparatus is assembled. The diaphragm 38 is formed of arelatively resilient material such as a food grade rubber, and is of athickness less than about 40/1000 of an inch. This thickness may varydepending upon the loads to be experienced by the diaphragm during useand the types of materials available for use in the diaphragm. Thesurface of the diaphragm 38 which is exposed to the lower interior space24 is preferably very smooth, having a roughness found acceptable forsuch uses by the food industry, e.g. less than about 15 R_(a).

The upper housing assembly 22 includes an upper housing 40 which is alsoprovided with a flange 42 of a size corresponding to the size of theflange 36. The upper housing 40 is adapted to mate with the lowerhousing 20 with the flanges 36, 42 opposing one another, and with thediaphragm 38 therebetween. A circular ring clamp 44 of conventionalconstruction is used to secure the housings 20, 40 and diaphragm 38together.

In addition, the upper housing 40 includes an upper interior space 46that is separated from the lower interior space 24 by the diaphragm 38when the apparatus is assembled such that the diaphragm and the lowerinterior space together define a fluid receiving cavity and the upperinterior space 46 is isolated from contact with the fluid being handledby the apparatus.

The ring clamp 44 is illustrated in more detail in FIG. 4, and includesa plurality of clamp sections 48 and securing means for securing theclamp in place on the apparatus. The securing means includes a threadedrod 50, which is pivotally supported on one of the clamp sections 48 bya transverse pin 52, and a wing nut 54 or the like received on thethreaded rod.

Returning to FIG. 2, a valve 56 is provided within the fluid receivingcavity and includes a valve closure member 58 disposed in the inletconduit 26 opposite the constriction 30 from the fluid receiving cavity,and a lower stem element 60 extending between the valve closure member58 and the diaphragm 38 so that the closure member and diaphragm aremovable together. When the diaphragm 38 is in a position biased towardthe lower interior space 24, the closure member 58 is in aflow-permitting position such as that shown in FIG. 2, wherein theclosure member is separated from the constriction 30 by a distancesufficient to permit the flow of fluid around the closure member andinto the fluid receiving cavity.

If the diaphragm 38 is moved in a direction toward the upper interiorspace 46 from the flow permitting position, the closure member 58 ismoved into a flow-preventing position in which the closure member seatsagainst the constriction 30 to prevent the flow of fluid into the fluidreceiving cavity. The closure member 58 is formed of a food gradematerial, preferably plastic, and is attached to the lower stem element60 by a suitable adhesive which may be applied between a recess 62 ofthe closure member 58 and a relatively small diameter protrusion 64formed on the end of the lower stem element 60. Also, as shown in FIG.6, the closure member 58 includes a plurality of radially extendingfingers 66 which center the closure member within the inlet conduit 26while permitting fluid to flow around the closure member.

The stem element 60 is illustrated in FIG. 2, and is also preferablyformed of a food grade material such as a food grade plastic. The stemelement is provided with one or more ridges 68 adjacent thediaphragm-engaging end thereof. These ridges 68 provide a secureconnection between the stem element 60 and a central hub 70 of thediaphragm 38 when the diaphragm is fastened or molded to the stemelement.

An upper stem element 72 is also connected to the central hub 70 of thediaphragm 38 and extends in a direction opposite to the direction inwhich the lower stem element 60 extends. The upper stem element 72extends through the upper interior space 46 and includes an end locatedoutside of the upper housing 40 such that the position of the diaphragm38, and thus the closure member 58, may be confirmed simply by notingthe position of the end of the upper stem element relative to the upperhousing. Thus, it is possible to determine whether the closure member 58is in a flow-permitting or flow-preventing position merely by checkingthe position of the end of the upper stem element 72.

The upper stem element includes a bearing plate 74 in contact with thediaphragm 38 and adapted to bear against the diaphragm under the forceof a pressure regulating means. This regulating means includes acompression spring 76 disposed within the upper interior space collinearwith the upper stem element. The compression spring 76 is adapted toexert a predetermined compression load on the diaphragm 38 via thebearing plate 74 such that the diaphragm is normally biased toward thelower interior space 24 and the closure member 58 is retained in theflow-permitting position.

Adjustment means are provided on the upper housing assembly 22 foradjusting the magnitude of the force exerted on the diaphragm 38 by thecompression spring 76. The adjustment means includes an axially movablecollar 78 that is retained against rotational movement within the upperinterior space 46 of the housing 40 by two radially extending tabs 80,shown in FIG. 4, which ride in a pair o axial grooves 82 formed in theupper housing. The adjustment means also includes a rotatable sleeve 84interposed between the axially movable collar 78 and the upper stemelement 72 and being freely rotatable relative to the upper stemelement. The sleeve 84 and collar 78 are threaded and cooperate duringrotation of the sleeve to adjust the axial position of the collar withinthe upper housing 40.

A flange 86 is formed on the sleeve 84 intermediate the ends thereofwhich prevents the sleeve from moving through an opening 88 in the upperhousing. Axial movement of the sleeve in the opposite direction isprevented by the force exerted on the sleeve by the compression spring76.

In order to rotate the sleeve 84 to carry out an adjustment of theregulating force of the spring 76, a handle 90 is provided which isfixed to the sleeve 84 for rotation therewith. For example, the handle90 may be provided with a central opening having a squarecross-sectional shape corresponding to a square section of the sleeve sothat rotation of the handle translates into rotation of the sleeve 84.

Limit stop means are provided in the upper housing assembly 22 forlimiting the movement of the diaphragm 38 in the direction of the forceof the pressure regulating means. This limit stop means is necessary toprevent the compression spring 76 from pushing completely through thediaphragm material and into the lower interior space 24, and includes apin or protrusion 92 at the end of the upper stem element 72 which isadapted to abut the top end of the sleeve 84 when the limit position ofthe valve closure member 58 is reached. When the valve closure member 58is in the flow-preventing position, the pin or protrusion 92 is out ofcontact with the sleeve 84 and is elevated above the upper housing 40 bya noticeable height which serves as an indication of the closed positionof the closure member 58.

A further pin 94 is provided on the upper housing assembly 22 which maybe positioned in a hole 96 formed in the sleeve, as shown in FIG. 5, andwhich also may engage a groove 98 formed in the upper stem element 72 inorder to permit the upper stem element to be locked in theflow-permitting position. During normal operation of the apparatus 10,the pin 94 is removed from the hole 96 in the sleeve 84 and may bestored in an additional opening 100 provided on the upper housing.

During operation of the apparatus, the valve closure member 58 isnormally biased in the flow-permitting position such that fluid underpressure enters the fluid receiving cavity via the inlet conduit 26 andexits the cavity through the outlet conduit 28. This fluid is used insome known type of fluid handling equipment downstream of the valveapparatus wherein it is desired that the fluid be maintained at acertain substantially constant pressure.

Assuming that the pressure regulating means of the apparatus is properlyset, fluid is permitted to flow through the apparatus 10 until thepressure within the outlet conduit 28 and fluid receiving cavity reachesa pressure sufficient to cause the diaphragm 38 to move upward towardthe upper interior space 46 against the biasing force of the compressionspring 76. This upward movement of the diaphragm 38 is accompanied byupward movement of the closure member 58 toward the flow-preventingposition wherein the member is in contact with the constriction 30.Thus, the flow of pressurized fluid into the cavity is reduced orprevented until the pressure within the cavity and downstream thereoffalls to a threshold level at which the force of the spring 76 againmoves the diaphragm 38 and closure member 58 back toward theflow-permitting position.

If it is desired to alter the pressure level at which the diaphragm 38is moved to the flow-preventing position, the handle 90 is rotated inthe appropriate direction in order to reposition the collar 78 withinthe upper interior space 46. If the collar 78 is moved upward away fromthe spring 76, the spring is relaxed and the stored energy within thespring is reduced such that less force is exerted on the diaphragm 38.By making this adjustment, less pressure is required within the fluidreceiving cavity to cause movement of the diaphragm 38 and closuremember 58 to the flow-preventing position.

Alternately, if the collar 78 is moved downward toward the spring 76,the spring is further loaded creating a situation where greater fluidpressure is required to offset the greater spring force.

Because the apparatus is constructed with a fluid receiving cavity whichis generally free of mechanical parts and which is defined by wallshaving a polished surface, no voids or interstices are presented tofluid passing through the apparatus which might cause the fluid tostagnate or settle in dead spots. As mentioned above, such stagnation orsettling of many ingestible fluids permits solidification to occur orencourages germ growth which adversely effects the quality of thefluids.

Another benefit achieved through the provision of the apparatus of thepreferred embodiment resides in the ease of assembly and disassembly ofthe apparatus. By providing means for easily breaking the apparatus downinto several parts, cleaning of the apparatus is simplified such thatmaintenance personnel are able to clean the parts more thoroughly thanif the apparatus was cleaned in place in the system.

In order to break the apparatus down into the individual componentsthereof, the clamp 44 is first removed permitting the upper housingassembly 22 to be removed from the lower housing 20, and allowing theupper stem element 72 to be removed from the hub 70 of the diaphragm 38.Thereafter, the lower interior space 24 may be accessed for cleaning byfolding back the diaphragm 38 or by pulling the diaphragm along with thelower stem element 60 and closure member 58 through the inlet conduit26.

The upper housing assembly 22 may be further broken down by removing thelimit stop pin 92 from the upper stem element 72 and the open-lock pin94 from the sleeve 84, and sliding the upper stem element through theopening 88. Once the upper stem element 72 is removed, the handle 90,sleeve 84, collar 78 and spring 76 may be slid from the upperstemelement 72 so that the device is substantially completely broken down.

It is also possible to clean the apparatus while it is in place in thefluid handling system without upsetting the pressure regulating means orthe regulation adjustment means by locking the diaphragm 38 and closuremember 58 in the flow-permitting position so that cleaning fluid such assteam may be passed through the fluid receiving cavity to carry out acleaning operation. As mentioned, in order to lock the diaphragm 38 andclosure member 58 in the flow-permitting position, the pin 94 isinserted in the hole 96 when the annular groove 98 of the upper stemelement 72 is aligned therewith.

In this manner, the diaphragm 38 is locked in the flow-permittingposition while the compression spring 76, collar 78, and sleeve 84 areleft in their respective adjusted positions so that the pressure levelat which the spring is set remains unchanged. Thereafter, when the pin94 is removed, the apparatus returns to a proper regulating position.

An upstream pressure regulating apparatus 110 constructed in accordancewith another aspect of the invention is illustrated in FIG. 3. Thisapparatus is similar to the downstream pressure regulating apparatus 10discussed above except for several modifications permitting adaptationof the apparatus 110 for use in controlling the pressure of fluidupstream of the apparatus rather than the downstream pressure.

For example, in the upstream pressure regulating apparatus 110, an inletconduit 112 enters a lower interior space 114 through the side of alower housing 116 and an outlet conduit 118 is provided at the bottom ofthe housing and is substantially perpendicular to the inlet conduit 112.The outlet conduit 118 includes a constriction 120 adjacent the lowerinterior space 114.

An upper housing assembly 122 is provided with an upper housing 124which includes an interior space 126 that opposes the lower interiorspace 114 when assembled. A deformable diaphragm 128 separates theinterior spaces 114, 126 so that a fluid receiving cavity is defined bythe lower interior space and the diaphragm.

A valve 130 includes a valve closure member 132 disposed in the fluidreceiving cavity opposite the constriction 120 from the outlet conduit118. The valve closure member 132 includes an angled closure surface 134adapted to contact the constriction 120 to prevent the flow of fluidthrough the outlet conduit 118 when in a flow-preventing position. Theclosure member 132 is connected to the diaphragm 128 so that the closuremember and diaphragm are movable together between a flow-permittingposition in which the closure member is separated from the constriction120 and a flow-preventing position in which the closure member is inengagement with the constriction.

In this manner, the diaphragm 38 is locked in the flow-permittingposition while the compression spring 76, collar 78, and sleeve 84 areleft in their respective adjusted positions so that the pressure levelat which the spring is set remains unchanged. Thereafter, when the pin94 is removed, the apparatus returns to a proper pressure regulatingposition.

An upper stem element 136 connects to the diaphragm 128 and extendsthrough the upper interior space 126. The upper stem element 136includes an upper end disposed exterior of the upper housing 124. Theupper housing assembly 122 further includes a pressure regulating spring138 for exerting a force on the diaphragm 128 in a direction toward thelower interior space 114 such that the closure member 132 is normallybiased toward the flow-preventing position.

In this manner, the apparatus 110 prevents the flow of fluid through theoutlet conduit 118 unless and until the pressure in the fluid receivingcavity, and thus the inlet conduit 112, is at a pressure above a minimumthreshold required to lift the diaphragm 128 and closure member 132against the force of the compression spring 138 away from contact withthe constriction 120. As shown in FIG. 7, a lower end of the closuremember 132 defines a plurality of radially extending centering arms 140which align the closure member with the constriction 120 whilepermitting flow past the closure member when the angled closure surface134 is out of contact with the constriction 120.

Regulating adjustment means are provided, as in the downstreamapparatus, for adjusting the force exerted on the diaphragm by thecompression spring 138, and includes a collar 142, sleeve 144 and handle146 as described above with reference to the apparatus 10.

Because the closure member 132 prevents the compression spring 138 frompushing the upper stem element 136 through the diaphragm 128, no limitstop is required in the upstream apparatus 110. However, closure memberopening means are provided to permit manual movement of the closuremember 132 and diaphragm 128 to the flow-permitting position. Forexample, in the preferred embodiment, a cam lever 148 is provided at theupper end of the stem element 136, and is pivotal about a pin 150 sothat, upon pivoting of the cam lever 148, the stem element 136 is raisedrelative to a sleeve 144 of the regulating adjustment means. Thismovement of the stem element 136 pulls the diaphragm 128 and closuremember 132 away from the constriction 120 to the flow-permittingposition and a pin 152 may be used to lock the stem element 136 inplace. Thereafter, cleaning of the fluid receiving cavity may be carriedout without upsetting the present position of the pressure regulatingmeans.

Although the beneficial results achieved from the use of either theupstream or downstream pressure regulating valve apparatuses are notrepeated here with reference to the upstream embodiment, it isunderstood that the same benefits are realized by both embodiments andthat the only differences between the two constructions are thosenecessary to permit the downstream apparatus to be used in an upstreampressure regulating environment.

Whereas the invention has been described with reference to theillustrated preferred embodiment, it is noted that substitutions may bemade and equivalents employed herein without departing from the scope ofthe invention as set forth in the claims.

What is claimed is:
 1. A fluid pressure regulating valve apparatuscomprising:a lower housing including a lower interior space; an upperhousing assembly including an upper housing defining an upper interiorspace, the upper housing including an opening extending between theupper interior space and an area exterior of the upper housing; adeformable diaphragm separating the lower interior space from the upperinterior space and, together with the lower interior space, defining afluid receiving cavity; a first conduit in fluid communication with thefluid receiving cavity, the first conduit defining a first conduit axis;a second conduit in fluid communication with the fluid receiving cavity,the second conduit defining a second conduit axis which is offset fromthe first conduit axis; a valve including a valve closure memberconnected to the diaphragm so that the closure member and diaphragm aremovable together between a flow-permitting position and aflow-preventing position; and an upper stem element connected to thediaphragm and extending through the upper interior space, the upper stemelement including an upper end extending through the opening and beingdisposed exterior of the upper housing, the upper housing assemblyfurther including pressure regulating means for exerting a force on thediaphragm in a direction toward the lower interior space and regulatingadjustment means for adjusting the force exerted on the diaphragm by thepressure regulating means, and limit stop means for limiting themovement of the upper stem element in the direction of the force of thepressure regulating means, the limit stop means being disposed outsidethe upper interior space adjacent the opening.
 2. The fluid pressureregulating valve as recited in claim 1, wherein the lower interior spaceincludes a surface adapted to be exposed to fluids being controlled bythe apparatus, the surface having a roughness of less than about 15R_(a).
 3. The fluid pressure regulating valve as recited in claim 1,wherein the diaphragm includes an annular diaphragm body having athickness of less than about 40/1000 of an inch.
 4. The fluid pressureregulating valve as recited in claim 1, wherein the axis of the secondconduit is substantially perpendicular to the axis of the first conduit.5. The fluid pressure regulating valve as recited in claim 1, whereinthe pressure regulating means includes a compression spring retained inthe upper interior space and positioned to exert a force on thediaphragm.
 6. The fluid pressure regulating valve as recited in claim 1,wherein the regulating adjustment means includes positioning means forchanging the position of the compression spring within the upperinterior space so that the force exerted on the diaphragm by the springis adjusted.
 7. An apparatus for regulating the downstream pressure of afluid being controlled by the apparatus, the apparatus comprising:alower housing including a lower interior space; an upper housingassembly including an upper housing defining an upper interior space,the upper housing including an opening extending between the upperinterior space and an area exterior of the upper housing; a deformablediaphragm separating the lower interior space from the upper interiorspace and, together with the lower interior space, defining a fluidreceiving cavity; an inlet conduit in fluid communication with the fluidreceiving cavity, the inlet conduit defining an inlet axis and includinga constriction; an outlet conduit in fluid communication with the fluidreceiving cavity, the outlet conduit defining an outlet axis which isangled relative to the inlet axis; a valve including a valve closuremember disposed in the inlet conduit opposite the constriction from thefluid receiving cavity, and a lower stem element extending between thevalve closure member and the diaphragm so that the closure member anddiaphragm are movable together between a flow-permitting position inwhich the closure member is separated from the constriction and aflow-preventing position in which the closure member is in engagementwith the constriction; and an upper stem element connected to thediaphragm and extending through the upper interior space, the upper stemelement including an upper end extending through the opening and beingdisposed exterior of the upper housing, the upper housing assemblyfurther including; pressure regulating means for exerting a force on thediaphragm in a direction toward the lower interior space, regulatingadjustment means for adjusting the force exerted on the diaphragm by thepressure regulating means, and limit stop mans for limiting the movementof the diaphragm in the direction of the force of the pressureregulating means, the limit stop means being disposed outside the upperinterior space adjacent the opening.
 8. An apparatus for regulating thedownstream pressure of a fluid being controlled by the apparatus, theapparatus comprising:a lower housing including a lower interior space;an upper housing assembly including an upper housing defining an upperinterior space, the upper housing including an opening extending betweenthe upper interior space and an area exterior of the upper housing; adeformable diaphragm separating the lower interior space from the upperinterior space and, together with the lower interior space, defining afluid receiving cavity; an inlet conduit in fluid communication with thefluid receiving cavity, the inlet conduit defining an inlet axis andincluding a constriction; an outlet conduit in fluid communication withthe fluid receiving cavity, the outlet conduit defining an outlet axiswhich is angled relative to the inlet axis; a valve including a valveclosure member disposed in the inlet conduit opposite the constrictionfrom the fluid receiving cavity, and a lower stem element extendingbetween the valve closure member and the diaphragm so that the closuremember and diaphragm are movable together between a flow-permittingposition in which the closure member is separated from the constrictionand a flow-preventing position in which the closure member is inengagement with the constriction; and an upper stem element connected tothe diaphragm and extending through the upper interior space, the upperstem element including an upper end extending through the opening andbeing disposed exterior of the upper housing, the upper housing assemblyfurther including; pressure regulating means for exerting a force on thediaphragm in a direction toward the lower interior space, regulatingadjustment means for adjusting the force exerted on the diaphragm by thepressure regulating means, limit stop means for limiting the movement ofthe diaphragm in the direction of the force of the pressure regulatingmeans, and lock-open means for locking the closure member and diaphragmin the flow-permitting position.